Salts of dialkylaminoarylphosphinous acids and process of making them



Patented May 1, 1934 s A L 'r s 0F DIALKYLA'MI'NOARYLPHOS- PHINOUS ACIDSAND PROCESS OF MAK- ING THEM Louis Benda, Frankfort-on-the-Main,Germany, assignor to Winthrop Chemical Company, Inc., New York, N. Y., acorporation of New York No Drawing. Application June 3, 1933, Serial No.674,259. In Germany July 24, 1931 They are, however, not stable in asolid state, but

after being stored for a short time they show signs of decompositionalready at ordinary temperature and they assume a disagreeable odor andtaste. Therefore, they could hitherto not :be administered orally.

Now I have found that completely stable products, which do not decomposeat an elevated temperature, are obtained by heating in an open vesselcrystallized salts of the following formula wherein X stands for analkyl radical, Y for hydrogen or a substituent of the group consistingof alkyl, alkoxy and dialkylamino, and Z for an alkaline earth metal.

This operation is preferably carried out at a temperature between aboutC. and about 120 C. The salts may be heated under a reduced pressure.The duration of heating depends upon the degree of temperature and thepressure. It varies between about 2 hours and about 4 days. The heatingoperation is preferably continued until the weight of the substanceheated remains constant.

The following compounds, for instance, may be subjected to the processdescribed: the calcium salt of4-dimethylamino-2-methylbenzene-l-phosphinous acid; the strontium saltof -dimethylamino-2-methylbenzene-l-phosphinous acid; the barium salt of4-dimethylaminoQ-methyl benzened-phosphinous acid;

the calcium salt of 4-diethylamino-2-methylbenzene- 1 -phosphinous acid;

the calcium salt of 4-dimethylamino-Z-methoxybenzene-l-phosphinous acid;

the calcium salt of 4-dimethylamino-benzene-1- phosphinous acid; 1

the calcium salt of 4-dimethylamino-2-ethoxybenzene-l-phosphinous acid;the calcium salt of 4-dimethylamino-Z-dimethylaminobenzene-l-phosphinousacid; the calcium salt of4-dimethylamino-2diethylaminobenzene-l-phosphinous acid; the calciumsalt of -dimethylamino-Z-ethylbenzene-l-phosphinous acid.

The substances thus obtained may be stored for any time, also in tropicsand may be used in the form of a powder or tablets.

The following examples illustrate the invention:

(1) Crystallized calcium salt of 4-dimethylaminobenzene-l-phosphinousacid, as described in U. S. Patent No. 1,607,113, dated November 16,1926, is heated in a vacuum to 70 C. until no more loss of weightoccurs. A powder fine as dust is obtained which is soluble in water,methyl alcohol and ethyl alcohol. The reaction may also be carried outat a temperature between about 100 C. and about 120 C. without applyingreduced pressure.

(2) To a cold solution of 82.5 parts of the sodium salt of4-dlmethylamino-2-methylphenyll-phosphinous acid in 200 parts of waterthere is added, while stirring, a cold solution of 120 parts ofstrontium chloride in 120 parts of water. The mixture is allowed tostand for a prolonged time and then filtered by suction, washed withice-cold water and dried in the air. The product is boiled with alcoholand filtered with suction. The strontium salt thus obtained is dried inthe air at ordinary temperature and then heated in a vacuum to C. Thewhite product ob-- tained is rather readily soluble in Water, sparing-1y soluble in methyl alcohol and ethyl alcohol and almost insoluble inacetone. The air-dry strontium salt contains 2 molecular proportions ofcrystal-water.

This application is a continuation-in-part of U. S. application SerialNo. 623,011, filed July' 16, 1932.

oli-

I claim: 1. The process which comprises heating a crystallized compoundof the following formula:

wherein X stands for an alkyl radical, Y for hydrogen or a substituentof the group consisting of alkyl, alkoxy and dialkylamino, and Z for analkaline earth metal, at a temperature between about 70 C. and about 120C.

2. The process which comprises heating a crystallized compound of thefollowing formula:

wherein X stands for an alkyl radical, Y for hydrogen or a substituentof the group consisting of alkyl, alkoxy and dialkylamino, and Z for analkaline earth metal, at a temperature between about 70 C. and about 120C. under a reduced pressure.

3. The process which comprises heating a crystallized compound of thefollowing formula:

on H0 I P r wherein Y stands for hydrogen or a substituent of the groupconsisting of alkyl, alkoxy and dialkylamino, and Z stands for analkaline earth metal, at a temperature between about 70 C. and about 120C.

4. The process which comprises heating a crystallized compound of thefollowing formula:

wherein X stands for hydrogen or a substituent of the group consistingof alkyl, alkoxy and dialkylamino, and Z stands for an alkaline earthmetal, at a temperature between about 70 C. and about 120 C. under areduced pressure.

5. The process which comprises heating the crystallized calcium salt of4-dimethylaminobenzene-l-phosphinous acid at a temperature of about 70C. under a reduced pressure.

6. The process which comprises heating the crystallized strontium saltof i-dimethylamino- 2-methylbenzene-l-phosphinous acid at a temperatureof about 75 C. under a reduced pressure.

7. The products obtainable by heating a crystallized compound of thefollowing formula:

N X: NXz

OH H0 P 1' 2 wherein X stands for an alkyl radical, Y for hydrogen or asubstituent of the group consisting of alkyl, alkoxy and dialkylamino,and Z for an alkaline earth metal, at a temperature between about 70 C.and about 120 C. under a reduced pressure, said products being colorlessstable powders.

9. The products obtainable by heating a crystallized compound of thefollowing formula:

NwHm a)2 OH no I)\ /P 'o o 2 wherein Y stands for hydrogen or asubstituent of the group consisting of alkyl, alkoxy and dialkylamino,and Z stands for an alkaline earth metal, at a temperature between about70 C. and about 120 C., said products being colorless stable powders.

10. The products obtainable by heating a crystallized compound of thefollowing formula:

N(CH:)2 z):

Y -Y on HO l/ \l P P wherein Y stands for hydrogen or a substituent ofthe group consisting of alkyl, alkoxy and dialkylamino, and Z stands foran alkaline earth 150.

12. The product obtainable by heating the crystallized strontium salt of4-dimethy1amino-2- methylbenzene-l-phosphinous acid at a temperature ofabout C. under a reduced pressure, said product being a colorless stablepowder.

LOUIS BENDA.

